core: add new ConditionNeedsUpdate= unit condition

[elogind.git] / src / libudev / libudev-monitor.c

diff --git a/src/libudev/libudev-monitor.c b/src/libudev/libudev-monitor.c
index 4586b3d4c7bb7528d1da6427c21e22a9bf3c826e..186e5e1e87360e46ce458331138fa9686c7a5db7 100644 (file)
--- a/src/libudev/libudev-monitor.c
+++ b/src/libudev/libudev-monitor.c
@@ -96,7 +96,7 @@ static struct udev_monitor *udev_monitor_new(struct udev *udev)
 {
         struct udev_monitor *udev_monitor;
 
-        udev_monitor = calloc(1, sizeof(struct udev_monitor));
+        udev_monitor = new0(struct udev_monitor, 1);
         if (udev_monitor == NULL)
                 return NULL;
         udev_monitor->refcount = 1;
@@ -108,25 +108,28 @@ static struct udev_monitor *udev_monitor_new(struct udev *udev)
 
 /* we consider udev running when /dev is on devtmpfs */
 static bool udev_has_devtmpfs(struct udev *udev) {
-        struct file_handle *h;
-        int mount_id;
+
+        union file_handle_union h = {
+                .handle.handle_bytes = MAX_HANDLE_SZ
+        };
+
         _cleanup_fclose_ FILE *f = NULL;
         char line[LINE_MAX], *e;
+        int mount_id;
         int r;
 
-        h = alloca(MAX_HANDLE_SZ);
-
-        r = name_to_handle_at(AT_FDCWD, "/dev", h, &mount_id, 0);
-        if (r < 0)
+        r = name_to_handle_at(AT_FDCWD, "/dev", &h.handle, &mount_id, 0);
+        if (r < 0) {
+                if (errno != EOPNOTSUPP)
+                        udev_err(udev, "name_to_handle_at on /dev: %m\n");
                 return false;
-
+        }
 
         f = fopen("/proc/self/mountinfo", "re");
         if (!f)
                 return false;
 
         FOREACH_LINE(line, f, return false) {
-                _cleanup_free_ char *opts = NULL;
                 int mid;
 
                 if (sscanf(line, "%i", &mid) != 1)
@@ -147,21 +150,6 @@ static bool udev_has_devtmpfs(struct udev *udev) {
         return false;
 }
 
-/* we consider udev running when we have running udev service */
-static bool udev_has_service(struct udev *udev) {
-        struct udev_queue *queue;
-        bool active;
-
-        queue = udev_queue_new(udev);
-        if (!queue)
-                return false;
-
-        active = udev_queue_get_udev_is_active(queue);
-        udev_queue_unref(queue);
-
-        return active;
-}
-
 struct udev_monitor *udev_monitor_new_from_netlink_fd(struct udev *udev, const char *name, int fd)
 {
         struct udev_monitor *udev_monitor;
@@ -172,27 +160,29 @@ struct udev_monitor *udev_monitor_new_from_netlink_fd(struct udev *udev, const c
 
         if (name == NULL)
                 group = UDEV_MONITOR_NONE;
-        else if (streq(name, "udev"))
-                group = UDEV_MONITOR_UDEV;
-        else if (streq(name, "kernel"))
+        else if (streq(name, "udev")) {
+                /*
+                 * We do not support subscribing to uevents if no instance of
+                 * udev is running. Uevents would otherwise broadcast the
+                 * processing data of the host into containers, which is not
+                 * desired.
+                 *
+                 * Containers will currently not get any udev uevents, until
+                 * a supporting infrastructure is available.
+                 *
+                 * We do not set a netlink multicast group here, so the socket
+                 * will not receive any messages.
+                 */
+                if (access("/run/udev/control", F_OK) < 0 && !udev_has_devtmpfs(udev)) {
+                        udev_dbg(udev, "the udev service seems not to be active, disable the monitor\n");
+                        group = UDEV_MONITOR_NONE;
+                } else
+                        group = UDEV_MONITOR_UDEV;
+        } else if (streq(name, "kernel"))
                 group = UDEV_MONITOR_KERNEL;
         else
                 return NULL;
 
-        /*
-         * We do not support subscribing to uevents if no instance of udev
-         * is running. Uevents would otherwise broadcast the processing data
-         * of the host into containers, which is not acceptable. Containers
-         * will currently just not get any uevents.
-         *
-         * We clear the netlink multicast group here, so the socket will
-         * not receive any messages.
-         */
-        if (!udev_has_service(udev) && !udev_has_devtmpfs(udev)) {
-                udev_dbg(udev, "udev seems not to be active, disable the monitor\n");
-                group = 0;
-        }
-
         udev_monitor = udev_monitor_new(udev);
         if (udev_monitor == NULL)
                 return NULL;
@@ -290,7 +280,7 @@ _public_ int udev_monitor_filter_update(struct udev_monitor *udev_monitor)
             udev_list_get_entry(&udev_monitor->filter_tag_list) == NULL)
                 return 0;
 
-        memset(ins, 0x00, sizeof(ins));
+        memzero(ins, sizeof(ins));
         i = 0;
 
         /* load magic in A */
@@ -370,7 +360,7 @@ _public_ int udev_monitor_filter_update(struct udev_monitor *udev_monitor)
         bpf_stmt(ins, &i, BPF_RET|BPF_K, 0xffffffff);
 
         /* install filter */
-        memset(&filter, 0x00, sizeof(filter));
+        memzero(&filter, sizeof(filter));
         filter.len = i;
         filter.filter = ins;
         err = setsockopt(udev_monitor->sock, SOL_SOCKET, SO_ATTACH_FILTER, &filter, sizeof(filter));
@@ -598,7 +588,7 @@ retry:
                 return NULL;
         iov.iov_base = &buf;
         iov.iov_len = sizeof(buf);
-        memset (&smsg, 0x00, sizeof(struct msghdr));
+        memzero(&smsg, sizeof(struct msghdr));
         smsg.msg_iov = &iov;
         smsg.msg_iovlen = 1;
         smsg.msg_control = cred_msg;
@@ -743,7 +733,7 @@ int udev_monitor_send_device(struct udev_monitor *udev_monitor,
                 return -EINVAL;
 
         /* add versioned header */
-        memset(&nlh, 0x00, sizeof(struct udev_monitor_netlink_header));
+        memzero(&nlh, sizeof(struct udev_monitor_netlink_header));
         memcpy(nlh.prefix, "libudev", 8);
         nlh.magic = htonl(UDEV_MONITOR_MAGIC);
         nlh.header_size = sizeof(struct udev_monitor_netlink_header);
@@ -770,7 +760,7 @@ int udev_monitor_send_device(struct udev_monitor *udev_monitor,
         iov[1].iov_base = (char *)buf;
         iov[1].iov_len = blen;
 
-        memset(&smsg, 0x00, sizeof(struct msghdr));
+        memzero(&smsg, sizeof(struct msghdr));
         smsg.msg_iov = iov;
         smsg.msg_iovlen = 2;
         /*